Jambs mcnab and adam carr



JAMES MCNAB AND ADAM CARR, 0F NEW YORK, N. Y.

STEAM STOP-VALVE.

Specification of Letters Patent No.

To all 'whom 'it may concern.'

Be it known that we, JAMES MCNAB and ADAM CARR, of the city, county7 andState of New York, lhave invented a new and Improved Method ofConstructing Steam Stop- Valves to Facilitate the Repairs of the SameWhen Required; and we hereby declare that the following is a full andexact description thereoi'7 reference being had to the accompanyingdrawings and to the letters of reference marked thereon.

The nature of the invention consists in constructing the spindle andvalve A, A, in such a way that the valve can be readily reground. Theusual way of constructing steam valves is to have the screw cast withthe spindle entire, the consequence of which is that when the valve Abecomes leaky and requires regrinding it cannot be effected except withgreat diiiiculty.

The nature of our invention consists in connecting with the valvespindle A an outer shell with a screw as shown by the red colored partof the drawing B B. This outer screw B B is slipped over the valvespindle A and secured in its place by the screw (c) and athread also atthe bottom of the spindle as shown at D D for greater security. W'e alsohave 'improved the construction in the manner of packing the stuifingbox E E by inserting a small collar as shown at F F. The usual plan ofpacking steam valves is to put the packing in the entire space betweenthe top of the screw Gr 14,108, dated January 15, 1856.

and the under side of the cap H, there being nothing to preventl thepacking from getting into the thread of the screw I I. The insertion ofthe collar F F which is made perfectly tight to the outside leaves avery perfect chamber E E for the packing.

In case the valve becomes leaky7 which all stem valves are constantlyliable to, we unscrew the piece J J. 117e then run down the spindle A soas to bring the piece B B clear of the piece J J. We then draw the screwC and run the piece B B back again into- J J thereby slacking the screwat D D. We then put back the piece J J to its place. The spindle A andhand wheel K are then free to revolve truc without the-perpendicularmovement which raises the valve from the seat L L. The process ofregrinding is to place emery and oil on the valve and revolve thespindle as just described, the top piece H keeping the valve perfectlytrue without any other appliance being necessary.

l/Vhat we claim as our invention and desire to secure by Letters Patentis- The attachment of the outer shell B B to t-he valve spindle A A insuch a way that it can be removed at pleasure to repair the valve.

JAMES MGNAB. ADAM CARR. Vitnesses JOHN HARLIN, JAMES CAVANAGH.

